Snap-switch.



No. 718,495. Y PATBNTED JAN. 13, 1903.

G. A. MEAD.

SNAP SWITGH.

v.APPLIA'JIQI FILED SEPT. 3, 1901.

N0 MODEL.

NiTED STATES GEORGE A. MEAD, OF MAN'SFIELD, OHIO.

SNAP-SWITCH.

SPECIFICATION formingpart of Letters Patent No. 718,495, dated January 13. 1903- Appnmion sied september s. 1901. serai No. 74.117. (No man.)

.To all whom it 1v1/ty concern:

Be it known that I, GEORGE A. MEAD, a citizen of the United States, residing at Mansfield, inthe county of Richland, State of Ohio, have invented a certain new and useful Improvement in Snap-Switches, of which-'the following is a specification, reference being had therein to the accompanying drawings.

The invent-ion relates to electric snapswitches or quick-break switches designed to reduce to a minimum the Vsparking that occurs when the circuit is opened by the operation of the switch. V

One of the objects of the invention is to secure an easy initial manual operation of the switch while not impairing its final automatic snap action.

A second object is to economize in the amount of copper required in the switch.

A third object is to secure a compact construction and one not having projecting parts likely to give trouble.

A still further object is to increasethe durability of the device.

The invention will first be described in connection with the accompanying drawings, which illustrate the best form thereof which I have yet devised, after which the essential characteristics of the improvement willl be clearly pointed out and distinctly defined in the claims at the close of this speciiication.

In the drawings, Figure 1 is a side elevation of the switch in its closed condition. Fig. 2 is a similar elevation showing the switch in its position when being opened, when the automatic snap action is just about to occur. Fig. 3 is a plan View of the same.

Having reference to the drawings, 1 designates an insulating-base, upon which the operating parts of the switch are mounted.

2 are brassblocks mounted on said base near opposite ends of the same and having in connection therewith sockets or tubular portions 3 3, with binding-screws 4 4 arranged in the usual manner for receiving and securing the ends of the line-wires. In slots in the blocks 2- 2 are fixed the upright copper plates 5 6 and 7'8, forming the usual clips. In the left-hand clip, as Viewed in Fig. 1, the copuse of metal.

per blade 9 of thel switch is pivoted, while in the right-hand clip the free end of the said blade is inserted to complete the circuit.

The pivot of the blade 9 is shown constituted bya pin 10, inserted in corresponding holes through the clip and blade and provided wilh a Washer 11,'held in place by a key 12; but any well-known form of bolt may be substituted for the piu and key. The washer is formed concave or dlshed and has radial slots 121 cut in from the edges, so as to permit of a slight degree of spring or fiattening of the washer when its edge is pressed,

against the face of the clip with the concavity of the washer toward the clip, and the parts are so proportioned as to maintain said slight flattening or Iiexure, whereby the resiliency of the washer contracts the clip upon the blade 9 and preserves electrical contact between the said parts.

An arm 13 is pivoted on the blade 9 at an intermediate point thereon,this being my preferred' construction, because of its simplicity and because the parts may all be made of substantial proportions without unnecessary Some advantages of my invention, however, are secured equally well when the arm 13 is pivoted elsewhere than on-the blade 9, it being essential only that the arm shall be capable of motion independently of the blade. In the construction shown, however, the arm 13 has a yoke-shaped portion 14., which embraces the blade 9, a pivot-pin (indicated at 15) passing through corresponding holes in the yoke and blade. The shank of the ar'm lies along the top of the blade 9 and at the end of the latter is odset downward and provided with a handle 16, projecting in the same general direction as the blade, for manipulating the switch.

In order to provide for the ready initial manual :operation of the switch and at the same time to increase the rapidity and force of the nal automatic or snap action thereof, I arrange a spring 20 in connectionwith the blade and arm in the following manner: The spring is composed of a strong wire doubled in the middle, so as to form a loopor bight 21. The said loop or bight is received in a notch 22 in the upper surface of the arm 13. Preferably to prevent the possible unseatinp; of the bigzht 21 from the notch 22 a hook 23 is formed integral with the arm adjacent to the notch. From the bight the two branches of the spring extend on opposite sides of the arm straight or substantially straight, as at 24, to or nearly to the pivot-pin 15, where said branches are coiled into two or three turns, as at 25, and thence the end portions 26 thereot', which are straight or nearly straight, run to anchoring-screws 27 in the blade 9, around which the extremities 28 of the Wire are wrapped.

The construction just described enables me to proportion the spring so that the straight portions 24 thereof are longer than the straight portions 26 thereof, whereby the initial manual operation of the switch is facilitated, while when said manual operation is complete, as in Fig'. 2, and the snap action of the switch is about to occur the spring is not only at an increased tension, but is exerting said tension most eflectively on the blade 9.

By disposingr the coils in line with the pivot-pin 15, though not in contact with the same, (the clearance being shown in Fig. 2,) the spring is left perfectly free in its action, while at the same time practically all bodily displacement of the coils of the spring during the operation of the switch is obviated. The resiliency of the spring is largely derived from the coil, and the latter is not in any manner restrained from expending its entire retractile force in snapping the switch open.

In addition practically no movement takes place between the bigrht 2l of the spring and the arm 13 where said parts come in contact with each other, nor between the extremities 28 of the spring and the anchoring-screws 27. Hence wear on these parts is reduced to a minimum.

The yoke 14 of the arm 13 is extended in hook shape at beyond the pivot 15, preferably being so formed on each side of the blade 9. The hook or hooks 35 coperate with a pin 3G, set in the blade and projecting at each side of the latter in such position as to be engaged by said hooks after the handle of the switch has been raised. Such engagement, however, only occurs in the event that when the spring has been put under its desired full tension the frictional hold exerted by the clip 7 8 upon the blade 9 is too great )o be overcome by said tension. In such con- ;ingency the engagement of the hooks 35 with the pin 3G carries the blade positively upward with the arm 13 until said frictional hold is sufficiently diminished to be overcome by the Spring.

The switch constructed as above described is compact and has no objectionable projecting parts, is strong and light, requires a small amount of copper in its construction, is readily operated manually, and performs its automatic action in such a manner as to reduce sparking to a minimum.

What I claim is- 1. In a snap-switch, the combination with two terminals, of a pivoted blade adapted to electrically connect said terminals, an operating-arm pivotally mounted on said blade at a point removed from the pivotal point of the latter, and a spring having coils which are adjacent to the pivotal point of said arm and which spring has straight portions connected respectively with the said arm and blade.

2. In a snap-switch, the combination with two terminals, ot' a pivoted blade adapted to electrically connect said terminals, an operating-arm pivctally mounted on said blade at a point removed from the pivotal point of the latter, and a spring having coils which are adjacent to the pivotal point of said arm and which spring has straight portions connected respectively with the said arm and blade, the straight portion of said spring which is connected with the said arm being relatively long, and the straight portion of said spring which is connected with said blade being relatively short.

3. In a snap-switch, the combination with two terminals, of a pivoted blade adapted to electrically connect said terminals, and an operating arm pivotally mounted on said blade at a point removed from the pivotal point of the latter, a spring connecting said arm and blade, and contact parts which permit a limited movement of said arm relative to the said blade when the said spring is being placed under tension, but which causes the said blade to be positively moved by said arm should the spring fail to move the said blade when the arm has completed a certain limited movement in opening the switch.

In testimony whereot I afx my signature in presence of two witnesses.

GEORGE A. MEAD.

Witnesses:

C. H. HUsToN, F. M. PIKE.

ICO 

